This application requests continued support for the operation of a Core Facility in Mass Spectrometry within the Diabetes Research and Training Center at Washington University. the overall goal of the core is to support diabetes research. The core is an important component of the Mass Spectrometry Resource supported by the Division of Research Resources, Biotechnology Resources Program. The specific aims of the core are to: 1) Train investigators how to use GC/MS systems and the principles of mass spectrometry. 2) Allow use of GC/MS systems by investigators and their previously trained senior technicians. 3) Provide consultation regarding methodology, data interpretation and problem solving. 4) Provide limited services (quantitative, spectral analysis) for low volume users. 5) Support collaborative research by NIH funded diabetes investigators and leading investigators worldwide. 6) Continue to develop new GC/MS technologies to support diabetes research at Washington University and worldwide.